The invention relates generally to the fabrication of three-dimensional microstructures. In particular, the invention concerns laser etching and deposition techniques for forming three-dimensional microstructures in a vapor medium.
Known techniques for fine-scale three-dimensional patterning insufficiently serve the emerging field of micromechanics. As the field continues to develop, optimized mechanical structures will be required which will increasingly depart from the nearly two-dimensional regime of integrated circuit technology. Such optimized structures will exploit the benefits of a third dimension to increase forces and strengths, thereby affording more functionality in mechanical systems. Presently, even well-engineered macroscopic mechanical systems are difficult to imagine without free use of the third dimension.
Several adaptions to lithography, such as the LIGA (from the German Lithographic Galvanformung Abformung) x-ray technique, extend two-dimensional structures into greater height and provide some access into the third dimension. Lithography is, however, substantially limited to these merely quasi three-dimensional structures. Many applications, though, require a more versatile three-dimensional patterning technology which is more precise than the milling, welding and fastening technologies of existing macroscopic mechanical construction methods. In addition, there is a great need for techniques to assemble and package micromechanical systems.
Laser direct write technology refers to the laser induced etching or deposition of lines of material in or on a substrate. It has been developed for the repair and trimming of microelectronics in primarily two-dimensional applications. The emphasis, however, has been processing of nearly planar surfaces at micrometer or submicrometer resolution in two dimensions. The technology has not been developed to address the requirements of three-dimensional micromachining.
Some of the requirements of three-dimensional micromachining include speed, edge acuity, and resolution in the third dimension (depth). Texture and finish are also important, as well as compatibility with the processes and materials of current silicon micromachining. Micrometer scale precision and freedom from process induced damage of important electronic or mechanical structures are essential features for technology directed to the fabrication and assembly of microelectromechanical systems.
It is an object of the invention, therefore, to provide a process for producing three-dimensional microstructures that enables high resolution and profile versatility in the third dimension.
It is another object of the invention to provide a process for producing three-dimensional microstructures which is suitable for semi conductor fabrication applications.
Still another object of the invention is to provide a system for producing three-dimensional microstructures.
Yet another object of the invention is to provide a class of three-dimensional microstructures.